Siftproof plastic bag



A a 12, 1969 E. KUGLER 3,460,741

SIFTPROOF PLASTIC BAG Filed Feb. 12, 1968 F/az I 4 //d 2" E E 56 I I 5 2w Eli I a I INVENTOR. mat/:4 4442a,

A T'IOR NEYS United States Patent O ice 3,460,741 SIFTPROOF PLASTIC BAG Emanuel Kugler, 124 Richmond Place, Lawrence, N.Y. 11559 Filed Feb. 12, 1968, Ser. No. 704,725 Int. Cl. B65d 31/12, 33/28 US. Cl. 229-56 4 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to plastic bags, and more particularly to improvements for a plastic bag having a siftproof construction.

The bagging of granular or powdered material is complicated by the tendency of this difficult to handle material to leak or sift through heat seals. It is therefore desirable to minimize leakage with a double wall construction wherein a complete separate inner bag is actually operatively arranged with an outer bag. The material and production cost of such a bag is, as might be expected, greater than that of a single wall plastic bag and is probably the reason why double wall bags are so restricted in use. There is practically no utility for any currently known double wall bag apart from its siftproof feature or aspect.

Broadly, it is an object of the present invention to provide an improved siftproof bag having additional reuse value. Specifically, it is an object to provide an improved bag having a siftproof construction during primary use and the convenience of multiple internal compartments during subsequent reuse.

A siftproof bag demonstrating objects and advantages of the present invention includes an inner and outer bag construction and an upper gusset in the outer bag, preferably having a drawstring. Removal of the sealed contents of the bag necessitates rupturing of the gusset which then provides openings into compartments formed on opposite sides of the inner bag, a feature which greatly contributes to the reuse value of the bag.

The above brief description, as well as further objects, features and advantages of the present invention, will be more fully appreciated by reference to the following detailed description of presently preferred, but nonetheless illustrative embodiments in accordance with the present invention, when taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a perspective view of a first embodiment of a composite plastic bag according to the present invention;

FIG. 2 is a sectional view taken on line 2-2 of FIG. 1, illustrating the operative arrangement of the inner and outer plastic bags which form the composite bag of FIG. 1;

FIG. 3 is a perspective view of a second embodiment of of composite plastic bag according to the present invention;

FIG. 3A is a sectional view taken along the line 44 of FIG. 3;

FIG. 4 is a sectional view, similar to FIG. 3A, but illustrating the condition of the bag when filled with a product; and

FIG. 5 is a partial sectional view, on an enlarged scale, illustrating the manner in which the product is removed from the bag and also the formation of the compartments within the bag.

3,460,741 Patented Aug. 12, 1969 Reference is now made to the drawings, and in particular to FIGS. 1 and 2 illustrating a first embodiment of a composite bag according to the present invention, and herein generally designated 10. The composite bag 10 is constructed so that any leakage or sifting of any of the sealed contents from within the bag is minimized and, to this end, includes two plastic bags, namely, an outer bag 12 and an inner bag 14. Outer bag 12 is formed by the front and rear panels or walls 12a and 1212, respectively joined to each other along opposite side Welds 120. As best illustrated in FIG. 2, the front and rear walls 12a, 12b are integral at the portion coextensive with the upper end of the bag and, in a well understood manner, are provided with an inward fold forming a gusset 16 comprised of facing gusset walls 16a and 16b terminating in a lower fold line 16c. Operatively arranged in the gusset 16, and more particularly between the gusset wall sections 16a, 16b and the coextensive upper portions of the front and rear walls 12a, 12b, is a drawstring loop 18 constructed in the usual way from lengths of string stapled at their opposite ends, as at 20.

At the opposite end of the outer bag 12 there is a bagfilling opening 22 bounded by the lower edges respectively of the front and rear walls 12a, 12!).

As already noted, completing the construction of the composite bag 10 is an inner bag 14 having an operative position wherein as best illustrated in FIG. 2, the upper closed end 14a of the inner bag 14 has a clearancfi position below the gusset lower fold line 160. The significance of this will subsequently become apparent.

The opposite and open lower end of the inner bag 14 is joined, as by heat sealing 24, to the lower nd of the outer bag front and rear walls 12a, 12b and thus also bounds the lower bag-filling opening 2.2 for the composite bag 10.

The composite bag 10 formed in the manner just described of the two bags 12, 14 is particularly suitable for the packaging of difiicult to handle granular or powdered products since such materials are not apt to leak or sift from within the inner bag 14 because of the double wall construction. That is, the granular or powdered material is placed within the inner bag 14 through the bag-filling opening 22 and then the opening 22 is sealed closed by a heat seal line applied transversely across the bottom of the bag in the general vicinity of the heat seal edges 24. When it is desired to remove the sealed contents of the inner bag 14 it is necessary to rupture both the upper gusset 16 in the vicinity of the lower fold line of the gusset and the closed end 14a of the inner bag 14. In making these ruptures it is significant to note that after the contents is removed from the inner bag 14 the remaining bag is reusable and has openings communicating not only with the inner bag 14 but also with two side compartments 26 and 28, respectively, which are formed on opposite sides of the inner bag 14 by the walls of the inner bag and by coextensive portions of the front and rear walls 12a, 12b. Thus, the composite bag 10 elfec tively functions in the first instance as a siftproof bag which is particularly suitable for the packaging of powdered or granular products and thereafter as a convenient bag for reuse having three usable compartments.

The foregoing reusable aspect of the plastic bag 10 hereof is perhaps best illustrated by the second bag embodiment illustrated in FIGS. 3-6 and in which like parts are designated by the same but primed reference numerals. The significance difference in the bags 10 and 10' is the application of heat seal line segments 30 joining the gusset wall sections 16a, 16b to the upper portions of the front and rear walls 12a, 1212. Thus, in this embodiment of the composite bag 10', gusset compartments 32 are specifically formed to confine the drawstring loop 18.

As shown in FIG. 5, the product P is effectively sealed within the inner bag 14 by a lower heat seal 34 which closes the bag-filling opening 22' by joining together all walls of the outer and inner bags 12', 14' at their respective lower edges.

Having reference now specifically to FIG. 6, in order to remove the product P it is necessary to rupture the upper gusset 16' preferably in the vicinity of the lower fold line 160' thereof and also the upper sealed end 14a of the inner bag 14'. As a result of the rupturing of the gusset 16, openings 36 are formed respectively opening into each of the side compartments 26, 28' all as is clear- 1y illustrated in FIG. 6. Additionally, the rupturing of the closed end 14a naturally provides an Opening 38 for the inner bag 14.

For convenience in carrying the composite bags 10, 10', the outer bags thereon are preferably notched as at 40, 40', respectively.

What is claimed is:

1. A drawstring siftproof bag comprising a plastic outer bag including front and rear walls having a bag-filling opening in the lower end thereof, a gusset formed in the upper end of said outer bag including a pair of gusset wall sections operatively interposed between said front and rear walls and terminating in a lower fold line, a pair of side welds at the side edges of said front and rear walls and said gusset wall sections, a drawstring operatively arranged in said gusset between said gusset wall sections and the coextensive upper portions of said front and rear walls, and a plastic inner bag having an inner bag front wall and an inner bag rear wall formed of a single sheet of plastic and formed with a folded closed end and an open end having an operative position within said outer bag such that said open end is coextensive with said bagfilling opening, said inner bag front and rear walls being secured within said siftproof bag at said side welds below said gusset, said operative position of said inner bag being such that said folded closed end thereof has a clearance position below said gusset fold line whereby an opening in said gusset in the vicinity of said fold line opens into two separate bag compartments which are formed on opposite sides of said inner bag between said front wall of said outer-bag and said inner bag front wall as a first bag compartment and said rear wall of said outer bag and said inner bag rear wall as a second bag compartment.

2. A siftproof bag as defined in claim 1 wherein said front wall of said outer wall and said inner bag front wall are sealed together at their respective lower edges and said rear wall of said outer bag and said inner bag rear wall are sealed together along their respective lower edges to form a single lower opening into said siftproof bag into the inner bag thereof and sealing the bottoms of said bag compartments.

3. A siftproof bag as defined in claim 1 wherein the bottom edges of said front wall and rear wall of said outer bag and said inner bag front wall and said inner bag rear wall are all sealed together along a bottom seal closing said inner bag and said bag compartments.

4. A siftproof bag as defined in claim 3 wherein material to be packaged is contained within said inner bag.

References Cited UNITED STATES PATENTS 3,010,640 11/1961 Kugler 229-63 3,282,493 11/1966 Kamins et a1 229-54 3,283,994 11/1966 Miller 229-63 DAVID M. BOCKENEK, Primary Examiner U.S. Cl. X.R. 1 1; 22963 

